I've actually done some of this...exploring thing that we can do in Fallout, and I have to say, that I find about 70% of the place to be ridiculously blank and boring. Oh, Ruins and Dirt...Let's break that up with brown water and broken bridges. It totally fits the world, but it doesn't have the same intriguing locations as New Vegas did.
But, there is that 30% of places that are just awesome, or so well done or unique or whatever, but places that stand out within the barren wastelands, like Hoover Damn and New Vegas or Rivet City (That's the boat city right?).
For me, the number one place in all the Wastelands was the Glowing Sea, it felt so completely unique and awesome that it made me almost forget the radiation and killer...everything. \
So, what places did you enjoy visiting the most?
Glowing sea hands down, I love the radiation storms in general so being able to explore a place that is a constant one just increases that sense of joy I get when I see one rolling in :D Combining that with the fact that my current character is effectively immune to radiation (without power armor) and heals from it, I can explore the place for extended periods of time without having to worry.